Conventionally, JP-U-H06-86366 describes a card edge connector as a female connector having a connector with multi-stage connector terminals, which are arranged in a direction perpendicular to a substrate. The substrate as a male connector is a multi-layer board having multiple layers stacked in a certain order. An edge of an inner layer extends from an edge of an outermost layer to an outside of the substrate. Multiple terminals are arranged on each of the edge of the inner layer and the edge of the outer most layer. Thus, a step is formed between an inner card edge and an outer card edge in the substrate. The step is equal to a thickness of the substrate. The inner card edge is formed on the edge of the inner layer, and the outer card edge is formed on the edge of the outer most layer. With utilizing the step, the heights of the connector terminals connecting to the terminals of the inner and outer card edges are differentiated. Thus, the connector terminals provide multiple stages in the direction perpendicular to the substrate.
In the above card edge connector, since the step between the inner and outer card edges is formed with utilizing the thickness of the substrate, i.e., the thickness of the outermost layer, it is difficult to provide a sufficient height of the step. Accordingly, when the height of the step is small, it is necessary to prepare the connector terminals, which match the small height step. In this case, since a width between the connector terminals is narrow, so that the adjacent connector terminals are close. Thus, the connector terminals may contact with each other so that the terminals short-circuit.